MOT Risk Index.co.uk

Does the Mercedes-Benz 420 fail the MOT on lamps, reflectors and electrics more than it should?

The Mercedes-Benz 420 records 17.47 lamps, reflectors and electrics failure items per 100 initial MOT tests (2019–2024), against 29.52 expected for a car of the same age mix: less than expected for its class and age (−12.05, 95% interval −13.90 to −10.20). It ranks 642 of 729 models on lamps, reflectors and electrics (1 = most failures above expected).

Data release dvsa-2024-v2 (24 Sep 2026) · page updated 30 Sep 2026 · all models on lamps, reflectors and electrics · check a Mercedes-Benz 420 by registration

What exactly fails on lamps, reflectors and electrics?

The most frequent DVSA defect wording in this group on the Mercedes-Benz 420 is “The aim of a headlamp is not within limits laid down in the requirements”, recorded 144 times in 2019–2024.

Mercedes-Benz 420: most frequent lamps, reflectors and electrics defect wordings, 2019–2024 (30+ items each)
DVSA defect wordingItemsPer 100 tests
The aim of a headlamp is not within limits laid down in the requirements1444.34
A headlamp or light source missing, inoperative or more than ½ not functioning in the case of LED501.51
A lamp missing, inoperative or in the case of a multiple light source more than 1/2 not functioning411.23
A direction indicator lamp missing, inoperative or in the case of a multiple light source more than 1/2 not functioning401.20
An obligatory rear fog lamp missing, or a front or rear fog lamp inoperative or in the case of a multiple light source more than 1/2 not functioning401.20

Source: DVSA MOT bulk data (OGL v3.0) · Window: 2019–2024 · n = 3,320 (initial tests) · Method: failure items (major and minor) grouped by DVSA's defect tree; wordings with 30+ items · Updated: 30 Sep 2026 · Release: dvsa-2024-v2 · CSV

Other pages for this model

Mercedes-Benz 420 by postcode area · Mercedes-Benz 420 body, chassis and structure failures · Mercedes-Benz 420 brakes failures · Mercedes-Benz 420 noise, emissions and leaks failures · Mercedes-Benz 420 steering failures · Mercedes-Benz 420 suspension failures · Mercedes-Benz 420 tyres failures · Mercedes-Benz 420 visibility failures